U.S. patent number 8,161,966 [Application Number 11/842,778] was granted by the patent office on 2012-04-24 for respiratory muscle endurance training device and method for the use thereof.
This patent grant is currently assigned to Trudell Medical International. Invention is credited to Martin P. Foley, Jerry R. Grychowski.
United States Patent |
8,161,966 |
Foley , et al. |
April 24, 2012 |
**Please see images for:
( Certificate of Correction ) ** |
Respiratory muscle endurance training device and method for the use
thereof
Abstract
A respiratory muscle endurance training device (RMET) includes a
chamber and a patient interface. In one implementation, one or both
of a CO.sub.2 sensor or a temperature sensor can be coupled to the
chamber or patient interface to provide the user or caregiver with
indicia about the CO.sub.2 level in, or the temperature of, the
chamber or patient interface, and/or the duration of use of the
device. In another implementation, the RMET may have a fixed volume
portion adjustable to contain a measured portion of a specific
patient's inspiratory volume capacity. Methods of using the device
are also provided.
Inventors: |
Foley; Martin P. (London,
CA), Grychowski; Jerry R. (Lake Zurich, IL) |
Assignee: |
Trudell Medical International
(London, Ontario, CA)
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Family
ID: |
38983401 |
Appl.
No.: |
11/842,778 |
Filed: |
August 21, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20080096728 A1 |
Apr 24, 2008 |
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Current U.S.
Class: |
128/200.24;
128/200.12 |
Current CPC
Class: |
A61B
5/486 (20130101); A61B 5/0836 (20130101); A61B
5/097 (20130101); A63B 23/18 (20130101); A61B
5/01 (20130101); A63B 2230/433 (20130101) |
Current International
Class: |
A63B
23/00 (20060101) |
Field of
Search: |
;128/206.21,207.13,200.24,204.18,204.21,200.25,200.12,205.12
;482/13 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
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|
|
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199 12 337 |
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Aug 2000 |
|
DE |
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0 027 154 |
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Apr 1981 |
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EP |
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0 027 154 |
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Apr 1981 |
|
EP |
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0 372 148 |
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Jun 1990 |
|
EP |
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1 021 225 |
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Apr 1999 |
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EP |
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1 485 157 |
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Mar 2003 |
|
EP |
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1 377 347 |
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Jan 2004 |
|
EP |
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2 238 728 |
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Jun 1991 |
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GB |
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2 278 545 |
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Dec 1994 |
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GB |
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WO 01/39837 |
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Jun 2001 |
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WO |
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WO 02/081034 |
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Oct 2002 |
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WO |
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WO 2008/024375 |
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Feb 2008 |
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WO |
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Other References
Office Action (Non-Final) in U.S. Appl. No. 12/388,952, Foley et
al., mailed Dec. 10, 2010, 5 pages. cited by other .
International Search Report in International Application No.
PCT/US2007/018527, dated Feb. 20, 2008, 4 pages. cited by other
.
Written Opinion in International Application No. PCT/US2007/018527,
dated Feb. 20, 2008, 9 pages. cited by other .
Koppers, M.D., Ralph J.H., Vos, M.D., Ph.D., Petra J.E., Boot,
Ph.D., Cecile R.L., and Folgering, M.D., Ph.D., Hans Th.M.,
"Exercise Performance Improves in Patients With COPD due to
Respiratory Muscle Endurance Training," Manuscript--Original
Research COPD, American College of Chest Physicians
(www.chestjournal.org/misc/reprints.shtml), Apr., 2006, pp.
886-892. cited by other .
"FEMEN.RTM. CO.sub.2 Indicator--Innovative Technology for CO.sub.2
Indication," Engineered Medical Systems, Inc., Indianapolis, IN,
USA, date unknown, 2 pages. cited by other .
European Search Report in European Application No. 10 19 2608,
mailed May 3, 2011, 6 pages. cited by other .
Partial International Search Results for International Application
No. PCT/US2009/034474, dated May 18, 2009, 2 pages. cited by other
.
International Search Report in International Application No.
PCT/US2009/034474, dated Aug. 28, 2009, 8 pages. cited by other
.
Written Opinion of the International Searching Authority for
International Application No. PCT/US2009/034474, dated Aug. 28,
2009, 8 pages. cited by other .
International Preliminary Report on Patentability for International
Application No. PCT/US2007/018527, dated Feb. 24, 2009, 9 pages.
cited by other .
International Preliminary Report on Patentability for International
Application No. PCT/US2009/034474, dated Aug. 24, 2010, 7 pages.
cited by other .
U.S. Appl. No. 12/388,952 for "Respiratory Muscle Endurance
Training Device and Method for the Use Thereof" filed Feb. 19,
2009, for Foley, et al. cited by other.
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Primary Examiner: Donnelly; Jerome w
Attorney, Agent or Firm: Brinks Hofer Gilson & Lione
Claims
What is claimed is:
1. A respiratory muscle endurance training device comprising: an
adjustable chamber adjustable between at least a first interior
volume and a second interior volume, said adjustable chamber
comprising an output end, an input end spaced from said output end
and a one-way inhalation valve disposed proximate said input end;
and a patient interface connected to said output end of said
chamber.
2. The respiratory muscle endurance training device of claim 1
further comprising a one-way exhalation valve disposed proximate
said input end of said chamber.
3. The respiratory muscle endurance training device of claim 1
further comprising a flow indicator moveable in response to one or
both of an inhalation and exhalation.
4. The respiratory muscle endurance training device of claim 1
wherein said adjustable chamber comprises first and second tubular
members, wherein said first and second tubular members interface
and are moveable relative to each other between at least a first
and second position so as to define said first and second interior
volumes.
5. A respiratory muscle endurance training device comprising: an
adjustable chamber adjustable between at least a first interior
volume and a second interior volume, said adjustable chamber
comprising an output end; a patient interface connected to said
output end of said chamber; and a CO.sub.2 sensor coupled to at
least one of said chamber and said patient interface.
6. The respiratory muscle endurance training device of claim 5
wherein said CO.sub.2 sensor comprises a Fenem colorimetic
indicator disposed on an interior of one of said chamber and said
patient interface.
7. A respiratory muscle endurance training device comprising: an
adjustable chamber adjustable between at least a first interior
volume and a second interior volume, said adjustable chamber
comprising an output end; a patient interface connected to said
output end of said chamber; and a temperature sensor coupled to at
least one of said chamber and said patient interface.
8. The respirator muscle endurance training device of claim 7
wherein said temperature sensor is mounted on an exterior of said
at least one of said chamber and said patient interface.
9. A respiratory muscle endurance training device comprising: a
chamber comprising an output end; a patient interface connected to
said output end of said chamber, said patient interface and said
chamber defining an interior space; and a CO.sub.2 sensor
interfacing with said interior space and comprising user indicia
adapted to indicate at least one of a level of CO.sub.2 in said
interior space or a length of time of usage by a user.
10. A respiratory muscle endurance training device comprising: a
chamber comprising an output end; a patient interface connected to
said output end of said chamber, said patient interface and said
chamber defining an interior space; and a temperature sensor
coupled to at least one of said chamber and said patient interface
and comprising user indicia adapted to indicate at least one of a
temperature of said interior space, said chamber and said patient
interface or a length of time of usage by a user.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of pending U.S. Application No.
60/839,040, filed Aug. 21, 2006, the entirety of which is
incorporated herein by reference.
TECHNICAL FIELD
The present disclosure relates generally to a training device, and
in particular, to a respiratory muscle endurance training
device.
BACKGROUND
Patients with respiratory ailments, in particular patients with
COPD (Chronic Obstructive Pulmonary Disease), have impaired
exercise tolerance and diminished ventilatory efficiency. Various
techniques have been developed to improve respiratory muscle
endurance capacity. For example, one technique involves respiratory
muscle training through the use of positive expiratory pressure
devices, such as the AEROPEP PLUS valved holding chamber available
from Trudell Medical International, the Assignee of the present
application.
Another technique is referred to as Respiratory Muscle Endurance
Training (RMET). Most current RMET techniques require complicated
and expensive equipment, which limits widespread use.
Alternatively, a portable tube has been developed for use by COPD
patients, and has been effective in improving the endurance
exercise capacity of the users.
SUMMARY
A respiratory muscle endurance training device includes a chamber
and a patient interface. One or both of a CO.sub.2 sensor or a
temperature sensor can be coupled to the chamber or patient
interface to provide the user or caregiver with indicia about the
CO.sub.2 level in, or the temperature of, the chamber or patient
interface, and/or the duration of use of the device. In various
embodiments, one-way inhalation and exhalation valves and flow
indicators can also be associated with the chamber or patient
interface.
In one aspect of the invention, a respiratory muscle endurance
training device includes a patient interface for transferring a
patient's exhaled or inhaled gases and a fixed volume chamber in
communication with the patient interface, where the fixed volume
chamber is sized to retain a portion of a patient's exhaled gases.
A variable volume chamber in communication with the fixed volume
chamber, where the variable volume chamber is configured to be
responsive to the patient's exhaled or inhaled gases to move from a
first position to a second position. A variable orifice may be
positioned on the variable volume chamber to permit a desired
amount of exhaled air to escape during exhalation and to receive a
supply of air to replace the escaped exhaled air during
inhalation.
Methods of using the device are also provided. In particular, the
user inhales and exhales into the chamber. Over the course of a
plurality of breathing cycles, the CO.sub.2 level in the chamber
increases, thereby increasing the work of breathing and exercising
the user's lungs. In other embodiments, a visual or audible
indicator which may be located on the housing of the device may
provide flashes or beeps, respectively, to prompt a patient to
inhale or exhale at each such indication. In yet other embodiments,
a visual or audible indicator that is separate from the device may
be used to assist a patient in establishing the desirable breathing
pattern.
The various embodiments and aspects provide significant advantages
over other respiratory muscle training devices. In particular, the
training device is portable and the volume can be easily adjusted
to accommodate different users, for example those with COPD, as
well as athletes with healthy lungs. In addition, the user or care
giver can quickly and easily assess the level or duration of use by
way of various sensors, thereby providing additional feedback as to
the proper use of the device.
The foregoing paragraphs have been provided by way of general
introduction, and are not intended to limit the scope of the
following claims. The presently preferred embodiments, together
with further advantages, will be best understood by reference to
the following detailed description taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of one embodiment of a respiratory muscle
endurance training device.
FIG. 2 is a perspective view of an alternative embodiment of the
respiratory muscle endurance training device of FIG. 1.
FIG. 3 is a perspective view of the device of FIG. 2 during
exhalation with raised bellows.
FIG. 4 is a cross-sectional view of the device of FIG. 3 without a
flexible tube.
FIG. 5 is a top view of the device of FIGS. 2-3.
DETAILED DESCRIPTION
Referring to FIG. 1, a respiratory muscle endurance training device
includes a chamber 10, otherwise referred to as a spacer. In one
embodiment, the chamber includes a first chamber component 2 and a
second chamber component 3. In other embodiments, the chamber 10 is
formed as a single unitary component. The first and second chambers
define an interior volume 12 of the chamber.
In one embodiment, mating portions 14, 16 of the first and second
chambers are configured as cylindrical portions or tubes, with the
first chamber component 2 having an outer diameter shaped to fit
within an inner diameter of the second chamber component 3. One or
both of the chamber components are configured with circumferential
ribs 18 and/or seals (shown in FIG. 1 on the first chamber
component) that mate with the other chamber to substantially
prevent exhaled air from escaping from the chamber interface. In
one embodiment, the ribs 18 are spaced apart along the lengths of
one or both of the chamber components so as to allow the chambers
to be moved longitudinally in a longitudinal direction 20 relative
to each other and then fixed at different lengths depending on the
location of the ribs 18 and a mating shoulder 22 formed on the
other chamber (shown in FIG. 1 as the second chamber component).
The rings, or ribs, and shoulder are preferably integrally molded
with the chambers, although they can also be affixed separately,
e.g., as an o-ring. It should be understood that various detent
mechanisms, including springs, tabs, etc. can be used to index the
first chamber component relative to the second chamber component.
Of course, it should be understood that the chambers can also be
infinitely adjustable without any set detents, for example with a
simple friction fit between the chamber components.
When adjusted, the overall interior volume 12 of the chamber 10 can
be adjusted. For example, the interior volume 12 of the chamber can
be adjusted from between about 500 cc to about 4000 cc. The chamber
volume is adjusted depending on various predetermined
characteristics of the user, such as peak expiratory flow. In this
way, the interior volume 12 can be adjusted to reduce or increase
the total exhaled volume of expired gases captured inside the
chamber 10.
The first chamber component 2 includes an output end 24 that is
coupled to a patient interface 1. It should be understood that the
terms "coupling," "coupled," and variations thereof, mean directly
or indirectly, and can include for example a patient interface
in-molded with the first chamber at an output end thereof. The
patient interface can be configured, without limitation, as a mask,
a mouthpiece, a ventilator tube, etc. The term "output" merely
refers to the fact that gas or air moves through or from the
chamber to the patient interface during inhalation, notwithstanding
that gas or air moves from the patient interface into the chamber
during exhalation. The term "end" refers to a portion of the
chamber that has an opening through which the gas or air moves, and
can refer, for example, to a location on a spherical chamber having
such an opening, with that portion of the sphere forming the
"end."
The second chamber component 3 includes an input end 28, wherein
air or gas flows into the chamber 10. The chamber preferably
includes a one-way inhalation valve 5 that allows ambient air, or
aerosol from an aerosol delivery device, to flow in a one-way
direction through the input end 28 of the second chamber component
and into the interior volume 12. During an exhalation sequence of
the user, an exhalation valve 34 opens to allow exhaled gases to
escape to the ambient air. The inhalation valve 5 is preferably
configured as a duck-bill valve, although other valves such as slit
petal valves, center post valves, valves having a central opening
with a peripheral sealing edge, etc. would also work. One
acceptable valve is the valve used in the AEROPEP PLUS device,
available from Trudell Medical International.
The exhalation valve 34 is preferably formed around a periphery of
the inhalation valve. The second chamber 3 also includes a flow
indicator 36, formed as a thin flexible member disposed in a
viewing portion 38 formed on the second chamber, or as part of a
valve cap 6. The flow indicator is configured to move during
inhalation or exhalation to provide indicia to the user or
caregiver that an adequate flow is being generated in the device.
Various embodiments of the flow indicator and inhalation and
exhalation valves are disclosed for example and without limitation
in U.S. Pat. No. 6,904,908, assigned to Trudell Medical
International, London, Ontario, Canada, the entire disclosure of
which is hereby incorporated herein by reference. Examples of
various aerosol delivery systems and valve arrangements are
disclosed in U.S. Pat. Nos. 4,627,432, 5,385,140 5,582,162,
5,740,793, 5,816,240, 6,026,807, 6,039,042, 6,116,239, 6,293,279,
6,345,617, and 6,435,177, the entire contents of each of which are
incorporated herein by reference. A valve chamber 7 is coupled to
the input end of the second chamber. The valve chamber isolates and
protects the valves from being contaminated or damaged, and further
provides for coupling to a substance delivery device such as a tube
or an aerosol delivery device.
The chamber 10, for example the first chamber component 2 and/or
the patient interface 1, is configured with a CO.sub.2 sensor 4,
for example and without limitation a CO.sub.2 Fenem colormetric
indicator available from Engineering Medical Systems, located in
Indianapolis, Ind. The CO.sub.2 indicator 4 provides visual
feedback to the user and/or caregiver as to what the CO.sub.2 level
is in the chamber 10, or the interior spaced defined by the chamber
10 and the patient interface 1, to ensure that the CO.sub.2 level
is sufficient to achieve the intended therapeutic benefit. As shown
in FIG. 1, the sensor 4 is located at the output end of the chamber
10 adjacent the patient interface 1, or at the juncture of those
components, whether formed integrally or separately. Of course, it
should be understood that the sensor 4 can be located directly on
or in the patient interface 1, or on or in either of the first and
second chamber components 2, 3.
The expendable CO.sub.2 indicator 4 is configured with user indicia
to indicate the level of CO.sub.2 in the chamber or interior. The
indicator 4 includes a litmus paper with a chemical paper having a
chemical material that reacts to the CO.sub.2 concentration in a
gas. For example and without limitation, the color purple indicates
an atmospheric concentration of CO.sub.2 molecules less than 0.03%.
The color changes to a tan color at 2.0% CO.sub.2 in the gas. The
color yellow indicates 5.0% or more CO.sub.2 concentration. At this
level, the patient is re-inhaling expired gases (or dead space
gases) to increase the concentration of CO.sub.2 in the lungs of
the user, which encourages the user to inhale deeper, thereby
exercising the lung muscles to expand beyond their normal
condition. The sensor and indicator 4 can be used to determine the
CO.sub.2 level, or the length of the time the user has been using
the device. After use, the indicator 4 holds the reading for a
period of time, so that a caregiver who is temporarily absent can
get a reading after the use cycle is completed. Eventually the
indicator will reset by returning to its original color scheme,
such that it can be used again. The device is compact and
lightweight, and is thus very portable.
The device can also be configured with a temperature sensor 40,
such as a thermochromic liquid crystals strip, available from
Hallcrest Inc., Glenview Ill. The temperature sensor 40 is secured
to the outside (or inside) of one of the chamber or user interface.
A sensor can also be configured to measure the actual gas/air
temperature inside the chamber. In one implementation, the
temperature sensor 40 may utilize cholestric liquid crystals (CLC).
The temperature of the CLC is initially at room temperature. As the
user successively breathes (inhales/exhales) through the device,
the CLC will expand and contract depending on the temperature.
Depending on the temperature, the color of the indicator will
change, which also is indicative of, and can be correlated with,
the length of time the user has been breathing through the
device.
In one embodiment, an analog product line is used, which exhibits a
line that moves throughout the temperature cycle and provides a
direct correlation to the elapsed time of use. The temperature
indicator can be configured to provide for an indication of
temperature at least in a range from room temperature to slightly
below the body temperature of the user, e.g., 37 degrees
centigrade. A secondary temporal (e.g., minute) indicator can be
located adjacent to the temperature indicator to provide an
indication of how long the user has been using the device, with the
temperature being correlated with the elapsed time. Again, the
indicator can be configured to hold a reading, and then reset for
subsequent and repeated use.
The training device can be coupled to an aerosol delivery device
(not shown), such as a nebulizer or metered dose inhaler, to
deliver medication to the user through the chamber and patient
interface. In this way, the device performs two (2) functions, (1)
respiratory muscle endurance training and (2) treatment for
respiratory ailments or diseases such as COPD or asthma. In one
embodiment, the metered dose inhaler is engaged through an opening
formed in the valve chamber 7.
The materials used to manufacture the device may be the same as
those used to make the AEROCHAMBER holding chambers available from
Trudell Medical International of London, Ontario, Canada, which
chambers are disclosed in the patents referenced and incorporated
by reference above. The diameter of the chambers 10, 2, 3 can range
from between about 1 inch to about 6 inches. Although shown as
cylindrical shapes, it should be understood that other
cross-sectional shapes would also be suitable, including elliptical
and rectangular shapes, although for devices also used for aerosol
delivery, a cylindrical or elliptical shape is preferred to
minimize impaction and loss of medication prior to reaching the
patient.
An alternative embodiment of a respiratory muscle endurance
training (RMET) system 50 is illustrated in FIGS. 2-5. In this
embodiment, a tube 52 is connectable with a chamber which may have
a fixed volume portion 54 defined by a housing 56. A flexible
bellows 58 defines an adjustable volume portion 60. The tube 52 may
be of a diameter ranging from 22 mm to 40 mm that provides a dead
space volume (also referred to as rebreathing gas) of between 10
cubic centimeters (cc) to 40 cc per inch. The length may be varied
between 10 inches to 36 inches in one embodiment. The tube 52 may
be corrugated tubing made of polyvinyl chloride (PVC) and have
markings every six inches for reference when cutting to a desired
length. The fixed volume portion 54 defined by the housing 56 may
be manufactured in two sections to enclose 1600 cc, however it may
also be produced to have a volume in a range from 500 cc to 1600 cc
in order to cover an expected range of patients from the small and
thin to the large or obese.
The housing 56 may be constructed from a polypropylene material or
any of a number of other molded or formable materials. The housing
may be manufactured in two halves 55, 57 that are friction fit
together, glued, welded or connected using any of a number of know
connection techniques. Also, the housing 56 may be fashioned in any
of a number of shapes having a desired fixed volume. Hand rests 59,
which may also be used as device resting pads, may be included on
the housing 56. The bellows 58 may be manufactured from a silicone
or other flexible material and connected with the housing 56 at a
seal defined by a rim 62 on the housing 56 and a receiving groove
64 on the end of the bellows 58 that is sized to sealably grip the
rim 62. In other embodiments, the bellows may be replaced with a
balloon or other expandable body suitable for accommodating
variable volumes. In the implementation of FIGS. 2-4, the housing
56 may have a diameter of 6 inches and a height of 3.5 inches.
Other sizes may be fabricated depending on the desired volume of
gases.
As best shown in FIG. 2, the bellows 58 may be contained within the
housing 56 when no breathing is taking place using the system 50.
FIGS. 2-3 illustrate the RMET system 50 with the bellows extended
as a patient exhales. A volume reference member 66 having a scale
68 applied thereto or embedded therein may be mounted on the
housing 56. The scale may be a linear scale such as a scale
indicating increments of cc's, for example 100 cc increments from 0
to 500 cc. In one embodiment, the volume reference member 66 is
foldable against the housing 56 by hinges 67 on the housing to
permit a compact profile when not in use. An indicator 70 connected
with the bellows 58 moves with the bellows 58 during breathing so
that its position adjacent the volume reference member 66 on the
housing 56 will provide information relating to the volume for each
patient breath. FIG. 2 illustrates the RMET system 50 when the
bellows 58 are fully retracted, such as when the device is at rest
or a patient is inhaling. FIGS. 3-4 illustrate the system 50 with
bellows 58 extended during patient exhalation.
The cap 74 on the bellows 58 defines a variable orifice 72 which
may control the upper movement of the bellows 58 and define the
final volume of the adjustable volume portion 60. The variable
orifice 72 is set to allow excess exhaled gases to depart from the
system to help prevent the patient from inhaling more than a
desired percentage of the exhaled gases. In one embodiment, 60% of
exhaled gases are desired for inhalation (rebreathing). In the RMET
system 50 of FIGS. 2-4, the variable orifice 72 also acts to allow
fresh, inspired gases to enter into the system 50 when the patient
inhales more than the volume contained in the system 50. In this
manner, the additional 40% of gases necessary after the 60% of
exhaled gases have been inhaled may be breathed in. Preferably,
there are no valves in the variable orifice 72 in order to allow
the gases to flow freely through the system. By adjusting the
resistance of the variable orifice 72 to flow on exhalation, the
height of the bellows is adjusted during exhalation and the desired
mix of exhaled and fresh gases may be selected (in this example
60/40).
Referring to FIGS. 4-5, the variable orifice 72 may be formed by
overlapping portions, where an upper portion 76 has an opening 84
that may be rotated with respect to an underlying portion 78 to
selectively expose all or a portion of one or more openings 86 in
the underlying portion. The variable orifice 72 may be adjusted by
pushing against grips 80 extending out from the upper portion so
that the upper portion will rotate about a central axis. By pushing
against the grips 80 and turning the upper portion 76 with respect
to the lower portion 78 about a central axis 82, the opening 84 in
upper portion 76 may be aligned with one or more openings 86 in the
lower portion 78. Although a rotatable arrangement is illustrated,
other arrangements to vary an opening size are contemplated.
In operation, a patient first exhales into the patient interface,
which may be a mouthpiece 53, mask or other interface on the end of
the corrugated tubing 52. Upon the subsequent inhalation, the
patient will inhale expired gases located in the corrugated tubing
52, the fixed volume portion 54 and the adjustable volume portion
60, in addition to any additional fresh gas (such as ambient air)
entering into the system through the variable orifice 72 on the
flexible bellows 58. The amount of exhaled gases may be set to be
approximately 60% of the maximum voluntarily ventilation (MVV). To
calculate how the level of ventilation may be set to approximately
60% of MVV, one may multiply 35.times.FEV1 (forced expiratory
volume in the first second). This results in the relationship of
60% MVV=0.6.times.35.times.FEV1. The dead space of the RMET system
50, in other words the amount of volume for holding exhaled gases,
may be adjusted to 60% of the patient's inspiratory vital capacity
(IVC). The breathing pattern of the patient must be set above the
normal breaths per minute, which is generally 12 to 15 breaths per
minute. A breathing pattern between 16 to 30 breaths per minute may
be suitable depending on the patient. In the embodiments as
described herein, the breathing pattern is preferably 20 breaths
per minute. The embodiments as described herein may comprise a
visual or audible indicator to assist the patient in establishing
the desirable breathing pattern. For example, where the desired
breathing pattern is 20 breaths per minute a visual indicator, such
as a light, would flash on and off every 3 seconds prompting the
patient to inhale every time the light is on or every time the
light turns off. The visual or audible indicator could be located
adjacent the volume reference member 66. Although a mouthpiece 53
may be directly connected with the housing 56 as shown in FIG. 4,
the tubing 52 shown in FIGS. 2-3 permit greater flexibility in
customizing the amount of exhaled air retained in the system
50.
Assuming that, on average, a COPD patient's IVC is approximately
3.3 liters, 60% of 3.3 liters is approximately 2 liters. To achieve
this capacity with the RMET system 50, an accumulation of a fixed
volume plus a variable volume is used. The fixed volume with a
flexible tubing 52 (120 cc to 240 cc) plus a fixed volume portion
54 of 1600 cc defined by the housing 56, along with a bellows 58
adjustable between approximately 0 cc to 400 cc accounts for the
60% of the IVC. During exhalation, 40% of the expired volume of
gases may be expelled through the variable orifice 72 in the
bellows 58. During inhalation, the patient may inhale the exhaled
volume of gases in the system 50 and inhale the remaining 40% of
gases necessary to complete the IVC through the variable orifice 72
on the bellows 58. To adjust the volume of expired gases collected
from the patient, it is possible to reduce the length of the
corrugated tube and reduce the fixed volume of gas in the
device.
The patient observes the movement of the indicator 70 against the
scale 68 on the housing to determine that the 60% volume of the
patient's IVC has been reached. A separate or integrated timing
device (not shown), such as a mechanical or electronic timer
emitting an audible and/or visible signal, can assist the patient
to perform a breathing program at a sufficient rate of breaths per
minute. It is contemplated that the initial setting of the RMET
system 50 to 60% of a patient's specific IVC may be made by a
caregiver. The caregiver or patient may, for example, use a
pulmonary function machine to determine the patient's FEV1 which
can then be used to calculate the patient's MVV and ultimately 60%
of the IVC.
Although the present invention has been described with reference to
preferred embodiments, those skilled in the art will recognize that
changes may be made in form and detail without departing from the
spirit and scope of the invention. As such, it is intended that the
foregoing detailed description be regarded as illustrative rather
than limiting and that it is the appended claims, including all
equivalents thereof, which are intended to define the scope of the
invention.
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